Do you mean the page is going past your screen, as if the single window isnt enough to hold the entire page (you have to scroll over to see the rest of it)?
Or is it that the window is opening larger than the amount of space available?
We will need to know what operating system you are using. Either on your desktop, or in the Start menu, you should be able to find an icon titled "My Computer"
Right click on it, and click Properties.
It should list what operating system you are using on the "General" tab, and also some basic computer specifications that you might also consider listing (do not give us your serial number though)